Caster out of spec and vibration

[javamon]

Hi all - it's been a while, but I've got an interesting issue.

2006 3.0 6MT, 141k on the clock. Current symptoms: slight vibration at speed and caster is out of spec.

Fall 2015, I refreshed the front end myself (control arms, tie rods inner and outer, and ball joints), and had it aligned locally. I always thought the wheel was a bit off center, but it tracked true, and the refreshed front components made a world of difference - tie rod ends and control arm bushings were shot.

Jan 2017, I had the BMW dealer near here refresh the rear end components (that I had purchased back in fall 2015, but put off doing because of the PITA nature of the front end). Labor was actually reasonable, and I had them align it after. Result was Alignment 1 image attached - they noted the front strut was likely slightly bent and recommended replacement. It still drove wonderfully, minus the damping, with now fresh (less than 5k on front) bushings and joints, for about 3 weeks - then I started to notice a vibration creep in. Switch to summer tires did not cure or exacerbate.

April, 2017 - I went ahead and ordered Bilstein B4 dampers and mounts (every component but the springs on the struts) and changed out the extremely worn dampers. Fresh dampers, as usual, are a revelation. But the vibration remained. I went ahead and took it back to BMW for another alignment. Result of second alignment is attached as Alignment 2.

New strut fixed camber, but the caster is still out of spec evenly on both sides, and the slight vibration remains. In gear, clutch in still in gear, in neutral, under acceleration, coasting, braking, it doesn't make change the vibration. No associated noise. I don't feel anything at exactly one speed - a random 64mph, but anything past 60 and you notice it.

Thoughts? I am going to check wheel balance this week, but both winters (on wheels/tires with less than 4k on them) and summers (9" square style 63s, in ok shape) exhibit same vibration, so I'm assuming that's not the cause.

TL;DR - all new suspension components (everything in suspension but springs) within 5k miles, caster is out of spec and slight vibration at speed, stumped.

[zukgod1]

If the bottom one is the most recent I wouldn't bother with anything else.

Vibration wise, I'm dealing with this as well and I've narrowed it down to the CV shafts.
I've changed the brake rotors, all control arms, struts etc as you have.
I'm planning on chasing the shafts this next week I hope. Going OE as aftermarket isn't good on these trucks.

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[zukgod1]

FYI, I own a shop with my own alignment rack so really I wouldn't worry about the alignment as you posted.

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[javamon]

Sounds good re: the alignment - I wasn't completely worried about the caster, but still found it a little odd that it's out of spec, just barely, on both sides.

And yeah, rotors were my next thought after wheel balance - after that, the only other thing I could figure would be a bearing - but there's no play in the wheel when it's off the ground, and no noise, which is why I thought that was only a remote possibility.

If the CV does end up fixing it, I'd be interested in knowing.

[itsbrokeagain]

Did you do the front thrust arm bushings? You mentioned control arms, but which one? The short one that extends right and left, or the one that comes from the front and goes back to the spindle?

[javamon]

Originally Posted by itsbrokeagain

Did you do the front thrust arm bushings? You mentioned control arms, but which one? The short one that extends right and left, or the one that comes from the front and goes back to the spindle?

Yes - I did both sets of arms (upper and lower in my vernacular, but tension and wishbone according to realoem), the tie rods (inner and outer), ball joints, and sway bar (anti-roll) links.

If it moved or was a bushing, it got refreshed with lemforder or meyle HD parts. Same goes for the rear.

As far as the strut itself goes, everything is new except for the spring - that includes spring pads, upper and lower, strut bearing, bump stops, strut mount and hardware. Same for all corners.